1. Field of the Invention
The present invention pertains to a flush tank water conditioner of the type consisting of compressed water soluble disinfecting chemicals adapted for placement in the reservoir tank of conventional flush toilets and, more particularly, to a block of disinfectant composition placed in the refill tube of the reservoir tank to dissolve only during the flushing and refilling phase of the toilet operation and to signal impending depletion by the release of a dye material.
2. Discussion of the Prior Art
Stains and rings formed in porcelain toilet bowls as a result of water, frequently mineral rich, standing at a fixed level and disturbed only by irregular flushings creates a sanitary and aesthetic problem. A number of alternative approaches have been developed in the prior art to introduce disinfectant detergent agents into the elevated reservoir tanks of typical flush toilets to subsequently wash through the bowl to neutralize, condition and/or disinfect the toilet bowl water and thus to overcome this difficulty. Typically, ported dispensers containing water soluble treatment compounds are suspended within the toilet reservoir tank to automatically release a metered quantity of concentrated solution into the tank and/or bowl each time the water level within the tank is lowered and raised by the flushing sequence.
In U.S. Pat. No. 4,416,854 (Nielsen), a pair of electrolytically-reactive elemental metals, such as zinc and copper, are formed into chips and placed in a perforated container that hangs on the side of the toilet reservoir tank to submerge and activate the metals in the reservoir water producing a biocidal solution fatal to bacteria and algae yet not unsafe for human beings.
An analogous method of disinfecting toilet flushing water is taught in U.S. Pat. No. 4,229,410 (Kosti) wherein water soluble chemical agents are suspended in a mesh basket in the main drain tube below the drain closure valve between the toilet reservoir tank and the bowl rather than in the tank itself. Access for replacement is impractically difficult in this arrangement.
A closed container or tank that is inserted into the flow line between the float valve and overflow pipe houses a disinfectant disc or tablet and directs the flow of afterfill inlet water over and around the tablet after the toilet flushing operation is shown in U.S. Pat. No. 2,570,934 (Foster). The tablet container is clamped into position between the toilet tank top and the upper portion of the overflow pipe and access for tablet replacement is provided by a removable cover plate.
Passive dosing dispensers rely on the alternating cycles of flooding and syphoning of tank water through a chamber containing soluble disinfecting chemicals. These devices are dependent on the intervals between flushes to control concentrations. U.S. Pat. No. 4,281,421 (Nyquist et al) among others describes such a passive toilet tank dispenser that is immersed in the tank reservoir and receives water into an internal receptacle as the reservoir water level rises after a flush sequence. The internal receptacle is isolated from the tank by an air lock when the tank is full, and the entrapped water contacts a water soluble disinfectant cake to create a concentrated solution within the receptacle that is released to the toilet tank when a subsequent flush sequence lowers the tank level and breaks the air lock.
Dyes have been used to indicate the presence of disinfectant, as exemplified by the deep blue hue that accompanies water treated by a popular reservoir cleaning tablet, or to indicate the impending depletion of the disinfecting agent, as exemplified by U.S. Pat. No. 3,867,101 (Herring) wherein an indicator dye is enclosed in soluble disinfectant and released when the disinfectant dissolves to a predetermined level.
The prior art toilet tank water conditioner dispensers have generally suffered from one or more common disadvantages, namely a propensity to continuously dissolve between flushings causing wasteful over-concentration of treatment chemicals, unsightly support mechanisms visible outside the tank, awkward and inconvenient refill and replacement requirements, reliance on somewhat exact placement with respect to tank water levels and/or persistent discoloration of bowl water to indicate continuing disinfection.